CD8A and neoplasm: Gaydosik et al. [77] not only revealed intertumor T lymphocyte heterogeneity in cutaneous T-cell lymphoma (CTCL) skin tumors but also found that tumor-infiltrating CD8+ T lymphocytes exhibited heterogeneity in effector and exhaustion programs across patients, which provided an unprecedented view of lymphocyte heterogeneity in individual CTCL patients.